Every day, I fill it with ice water and it stays cold for as long as I need it to be. It's so well insulated that the ice is usually still there in full form when I'm finished with the cup.

Let's see what happens if you put hot water and cold water into room temperature water. Place a few ice cubes into a cup and add two tablespoons of water to make very cold water. Add 1 drop of blue ...

You might want to point out that 0 °C is the temperature at which water freezes so it’s pretty cold and that the temperatures below zero are even colder. 4. Do a demonstration to show how the ...